The present invention relates to a process for producing a toroidal winding with small dimensions and optimum geometry It is used with particular advantage in producing so-called sampling windings, which are used in magnetometers of the thin ferromagnetic film type.
Such a magnetometer is described in French Pat. No. 2 198 146. It comprises an insulating, e.g. quartz, cylinder on which is deposited a thin ferromagnetic film, which has a circumferential axis of easy magnetization. Such a means has a toroidal sampling winding wound around the cross-section of the cylinder supporting the film. FIG. 1 very diagrammatically shows the configuration of said winding. It is possible to see a hollow cylinder 10 for supporting the not shown magnetic film and a toroidal winding 12, whose turns are assumed to be in radial planes, i.e. in planes passing through the cylinder axis 13.
In view of the small dimensions thereof, in the prior art, the winding is manually wound. Therefore the orientation of the turns is not perfect. Although certain turns, such as turn 12a are located in a radial plane, others, such as turn 12b, are inclined with respect to such a plane. However, even more prejudicial defects are visible on turns 12c and 12d. Thus, in these different turns, there is, on the one hand, a direct coupling between the exciting coil and the sampling winding and, on the other hand, a misalignment between the normal to these turns and the circumferential easy magnetization axis. These two deficiencies lead to variations, errors and lack of reproducibility between individual magnetometers.